linux_aura: Fix crash on drags from the omnibox.

ui/views/view.cc

Index: ui/views/view.cc
diff --git a/ui/views/view.cc b/ui/views/view.cc
index 080df12881d63898fafcc4bb54ed63f7f78764f3..73b1e4ef2f2d39d7a6ae94fe98f7e566a12e75d2 100644
--- a/ui/views/view.cc
+++ b/ui/views/view.cc
@@ -9,6 +9,7 @@
 #include <algorithm>
 #include <cmath>
 
+#include "base/auto_reset.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
@@ -185,6 +186,7 @@ View::View()
       accessibility_focusable_(false),
       context_menu_controller_(NULL),
       drag_controller_(NULL),
+      currently_dragging_(false),
       post_dispatch_handler_(new internal::PostEventDispatchHandler(this)),
       native_view_accessibility_(NULL) {
   AddPostTargetHandler(post_dispatch_handler_.get());
@@ -194,6 +196,10 @@ View::~View() {
   if (parent_)
     parent_->RemoveChildView(this);
 
+  // If we destroy the view during a drag, AutoReset will probably write to
+  // freed memory.
+  DCHECK(!currently_dragging_);
+
   for (Views::const_iterator i(children_.begin()); i != children_.end(); ++i) {
     (*i)->parent_ = NULL;
     if (!(*i)->owned_by_client_)
@@ -2318,10 +2324,14 @@ bool View::DoDrag(const ui::LocatedEvent& event,
                   const gfx::Point& press_pt,
                   ui::DragDropTypes::DragEventSource source) {
 #if !defined(OS_MACOSX)
+  if (currently_dragging_)
+    return false;
+
   int drag_operations = GetDragOperations(press_pt);
   if (drag_operations == ui::DragDropTypes::DRAG_NONE)
     return false;
 
+  base::AutoReset<bool> updating_focus(&currently_dragging_, true);
   OSExchangeData data;
   WriteDragData(press_pt, &data);
 
@@ -2331,6 +2341,7 @@ bool View::DoDrag(const ui::LocatedEvent& event,
   ConvertPointToWidget(this, &widget_location);
   GetWidget()->RunShellDrag(this, data, widget_location, drag_operations,
       source);
+
   return true;
 #else
   return false;